CA2056294A1 - High speed recognition of a string of words connected according to a regular grammar by dp matching - Google Patents

Abstract

On carrying out connected word recognition in compliance with a regular grammar and in synchronism with successive specification of input feature vectors of the input pattern, one of an n-th word (n) of first through third occurrence (n(1) to n(3)) is selected as the n-th word of selected occurrence in an i-th period in which an n-th input feature vector is specified. The n-th word appears as the first through the third occurrence in transition rules specified by the grammar. In the n-th period, distances are calculated, only for the n-th word of the selected occurrence, between the input feature vector assigned to the i-th period and reference feature vectors for the n-th word. In the i-th period, a recurrence value g(n, i, j) is calculated only for the n-th word of the selected occurrence under a boundary condition T(p, i-l) iteratively in correspondence to the reference feature vectors by using the distances calculated for the n-th word of the selected occurrence before the i-th period, where j represents each feature vector. The recurrence value for the n-th word of nonselected occurrence is estimated by using the recurrence value for the n-th word of the selected occurrence and the boundary conditions T(p, i-l)'s for the n-th word of the selected and the nonselected occurrence. The above-mentioned one of the n-th word of the first through the third occurrence is selected so as to have a minimum value of the T(p, i-l)'s.